1. Field of the Invention
The present invention relates to a tool and, more particularly, to a welding gun.
2. Description of the Related Art
A conventional welding gun in accordance with the prior art shown in FIGS. 1 and 2 comprises an air inlet connector 1, a connecting member 2 connected with the air inlet connector 1, an air inlet pipe 3 extending from the air inlet connector 1 and extending through the connecting member 2 to allow introduction of a welding gas (such as carbon dioxide), a chuck 4 connected with the air inlet pipe 3 to allow insertion of an electrode 7, and an outer pipe 5 mounted on and located outside of the connecting member 2. A gap is defined between the outer pipe 5 and the air inlet pipe 3. The air inlet pipe 3 has a periphery provided with a plurality of vent holes 6. When in use, the welding gas flows through the air inlet connector 1, the air inlet pipe 3, the vent holes 6 of the air inlet pipe 3 and the gap between the outer pipe 5 and the air inlet pipe 3 and is injected outward from the outer pipe 5. However, when the welding gas flows through the vent holes 6 of the air inlet pipe 3 into the gap between the outer pipe 5 and the air inlet pipe 3, the welding gas is injected transversely to hit the inner wall of the outer pipe 5, thereby forming a turbulent flow, so that the pressure of the welding gas is unsteady and not evenly distributed, thereby causing an unsafe welding operation. In addition, the welding gas is unsteady and not evenly distributed so that the welding spot is not formed completely, thereby decreasing the aesthetic quality of the welding spot. Further, when the welding gas is unsteady, the electrode 7 and the welding gas are consumed and wasted. Further, the welding dregs produced during the welding process easily enter the outer pipe 5 to cause a choke so that the welding gas does not flow smoothly.